Clipped color channels - yikes - invalid comparison.
As I like to say: "If people are examining the corners of my images for sharpness, my images suck". In the Landscape forum, "Very sharp!" is what people say when the image bores them and they are trying to be positive.
That's not what corner sharpness is about. It is about the possibility to use the entire frame to present objects or especially texture with realism. When used that way, it contributes to the whole of the image, but the viewer will not be aware of it as corner sharpness, just a good image.
charlesk wrote:
I was really trying to give you benefit of the doubt on this "color separation" thing, but your comparison images are so ridiculous that I can't believe I bothered. Both images are both overexposed and oversaturated, and the Zeiss image is *more* overexposed *and* more oversaturated than the Canon image.
In short, these images prove absolutely nothing about anything, other than neither one of them was taken and processed properly.
Well, it certainly does prove that you can't read a histogram.
This is a classic example of the sort of technobabble that Zeiss fans are famous for: attempts to ascribe magical qualities to images when there are very simple explanations for what is being seen.
That was an explanation for somebody I thought needed a simple explanation. To somebody that doesn't know basic physics it might sound like magic. This is very basic physics. The technical term for is is constringence which is a measure of a material's dispersion as a function of the wavelength of the light. Glass with low dispersion per refractive index is expensive which is why cheaper lenses usually have poor color separation.
The "haze" over the EF 50 shot is because it has less contrast. This is clearly visible by comparing the luminosity histograms of the two shots. The mean and standard deviation luminosities for the Canon are 33.81 and 43.96; for the Zeiss, 35.15 and 47.35. Higher deviation from the mean in luminosity means more contrast. The brightness of the image is also 4% higher. These alone explain most of why the images look different in terms of colors.
Luminosity? Eh, think about that for a bit and you'll realize that it's one of the most nonsensical things posted in this thread so full of nonsense. Luminosity has nothing to do with colors. Luminosity is a channel in LAB space whose whole purpose is separating brightness levels from colors. If you want it in LAB mode it's the A & B channels you should look at - that's where the color information is.
It's the easiest thing in the world to show that an image captured with a lens with low constringence will have less color information than a lens with high constringence. That other things such as contrast also typically suffer with lenses that use cheap glass is besides the point. I could do a simple wavelet decomposition and show you the lack of any higher frequency components in the low constringence lens, but I won't bother as it's clear that you'll refuse to understand no matter how I explain it.
If you really want to learn something (I seriously doubt that tough), pick up a book on optics. I can recommend "The Manual of Photography" 10th edition by Elizabeth Allen et al. It covers the basics of optics and lens design pretty well.
If it wasn't for your hostility and rudeness I'd simply assume that your problem is ignorance. What you and a couple of others are doing is the equivalent of calling Maxwell's equations nonsense just because you have never taken a physics course. The stuff I've tried to explain to you is not the least bit controversial and it's essentially the same mechanism that is behind chromatic aberrations - the difference being the plane of diffraction and that CA is the sum effect of all elements.
However since you
a) apparently know very little of the subject and
b) will just continue to be rude if I try to explain it
Well, it certainly does prove that you can't read a histogram.
Feel free to present the histograms for our elucidation. Those images are full of clipped color channels.
That was an explanation for somebody I thought needed a simple explanation. To somebody that doesn't know basic physics it might sound like magic. This is very basic physics. The technical term for is is constringence which is a measure of a material's dispersion as a function of the wavelength of the light. Glass with low dispersion per refractive index is expensive which is why cheaper lenses usually have poor color separation.
Fascinating. Also not relevant to the matter at hand, at least not to any extent that you can actually demonstrate.
Luminosity? Eh, think about that for a bit and you'll realize that it's one of the most nonsensical things posted in this thread so full of nonsense. Luminosity has nothing to do with colors. Luminosity is a channel in LAB space whose whole purpose is separating brightness levels from colors. If you want it in LAB mode it's the A & B channels you should look at - that's where the color information is.
The "L" in the Lab color space/model stands for "Lightness", not "Luminosity". They are not the same. A luminosity histogram is based on a weighted average of the red, green and blue channels and is a simple way of assessing the brightness and contrast of an image. I obviously didn't mention this as a way of talking directly about color. I brought it up to point out that while you hand-waved away explaining the differences between the images based on brightness and contrast, the images differ greatly in those respects, which affects color. The difference in brightness is immediately obvious upon comparing the images, and that is why I checked the histograms.
It's the easiest thing in the world to show that an image captured with a lens with low constringence will have less color information than a lens with high constringence.
Great, then please do so.
If it wasn't for your hostility and rudeness...
That's a two-way street, buddy. Don't criticize others for such and then say things like "If you want to learn something (I seriously doubt that though)", or make fun of my ability to read a histogram when you apparently don't even understand what a luminosity histogram *is*.
this is my exit from this thread.
PetKal wrote:
Kumar, seriously, as far as I am concerned, based on those "rendering" considerations, those shots might have been taken with little Canon 18-55 IS zoom or 50 f/1.8 MkI which are also sharp enough lenses.
However, either the St. Mary's cathedral roofline is crooked or your Zeiss lens has a nastily distorted drawing style.
Seriously, the kit lens? Ouch.
Both shots are slanting, the lens is heading back to Zeiss tomorrow!
Do you honestly believe there is something unique about those images? (that's rhetorical, btw)
Seriously though I think it's time for a lock on this thread--there is good discussion and then there is ridiculousness. If you want to share images made with any lens, be is Zeiss, Canon, Nikon, Sigma, etc etc start a separate thread.
When the bashing and irrelevant banter was rife this was a worthy thread. When pictures from the lens in question are shown, the thread should be locked.
SKumar25 wrote:
When the bashing and irrelevant banter was rife this was a worthy thread. When pictures from the lens in question are shown, the thread should be locked.
You claimed to have been done with the thread five days ago. If you don't like it, why don't you just participate in something else instead of trying to ruin it? Even though some of the exchange has been heated, it is still far more interesting than most of the discussions in the Canon forum.
SKumar25 wrote:
When the bashing and irrelevant banter was rife this was a worthy thread. When pictures from the lens in question are shown, the thread should be locked.
And you think, after carrying on for 27 pages, that a few images is going to save the thread? As I said, if you want to post images (not even what the thread was about from the get go) then start a fresh thread.
charlesk wrote:
You claimed to have been done with the thread five days ago. If you don't like it, why don't you just participate in something else instead of trying to ruin it? Even though some of the exchange has been heated, it is still far more interesting than most of the discussions in the Canon forum.
From my viewpoint, this thread was ruined right when comments became personal...which occurred long time ago. If everyone stuck to discussing the lens, we would have been fine, unfortunately, DPreview mentality took over and we have an out of control personal bashing thread.
denoir wrote:
[If you really want to learn something (I seriously doubt that tough),
Classy. And bad spelling. Or maybe you meant "tough." In which case I guess I am confused. ;-)
But do carry on.
I could do a simple wavelet decomposition...
Well, then, start up the band. I'd love to see you dance! ;-)
If it wasn't for your hostility and rudeness I'd simply assume that your problem is ignorance.
Uh, whose hostility and rudeness? ;-)
What you and a couple of others are doing is the equivalent of calling Maxwell's equations nonsense just because you have never taken a physics course.
Uh, no. Not even close.
... you
a) apparently know very little of the subject and
b) will just continue to be rude if I try to explain it
chez wrote:
From my viewpoint, this thread was ruined right when comments became personal...which occurred long time ago. If everyone stuck to discussing the lens, we would have been fine, unfortunately, DPreview mentality took over and we have an out of control personal bashing thread.
What is it with all the whining?
This is a discussion forum. We're discussing something. If you don't want to discuss it, go to another thread.
Why do the people who don't want to participate in a discussion have to constantly chime in complaining about it and trying to get it locked? Honestly.
As for "personal bashing", this barely moves the needle. Some of the comments have been a bit heated but I see very little personal animosity. People like yourself who only post talking about the thread and not the actual subject are not helping.
This is a discussion forum. We're discussing something. If you don't want to discuss it, go to another thread.
Why do the people who don't want to participate in a discussion have to constantly chime in complaining about it and trying to get it locked? Honestly.
As for "personal bashing", this barely moves the needle. Some of the comments have been a bit heated but I see very little personal animosity. People like yourself who only post talking about the thread and not the actual subject are not helping.
Well, I actually have a real interest in the threads original topic in that I am contemplating acquiring a zeiss 21mm lens for my landscape photos. I don't have a hell of a lot to offer in this thread as I don't have any experience with Zeiss...but none the less, I have a lot of interest.
What I don't have any interest for, in fact don't have time for, is the constant childish bickering going on between a few select members which ads squat to the original intent of this thread.
It is routine for threads to drift over time. There's only so much that can be said about the actual lens test that started the thread. People talk about that, and they say their peace, and then they go to related topics and the thread goes as it will. That's how it works.
This thread was never about the Zeiss 21mm at any rate, so how is that interest of any relevance? Regardless, if that's what you want to talk about, why not do so? It would certainly be more constructive than complaining about off-topic bickering by posting more off-topic bickering yourself.
Or you could start a new thread, you know. Nobody is forcing you to read this one if it doesn't suit your interests. But you not liking the direction it has gone is not a valid justification for trying to get it shut down for everyone else.
chez wrote:
From my viewpoint, this thread was ruined right when comments became personal...which occurred long time ago. If everyone stuck to discussing the lens, we would have been fine, unfortunately, DPreview mentality took over and we have an out of control personal bashing thread.
I have just received the Zeiss; and while I do not have the 100L with which to compare, I have owned the 100 macro and 180L macro. Both of the canon macros were great lenses. The zeiss has a much different signature; no suprise, and it also wonderful. It is early, however, I am impressed with what I have seen of the images taken with this well built 100. For me it is a keeper.
Actually, this has been a pretty good debate, 27 pages of lens talk without ONE shot of a duck or kid with food on their face. We are making progress here.
XsigmaSD wrote:
Actually, this has been a pretty good debate, 27 pages of lens talk without ONE shot of a duck or kid with food on their face. We are making progress here.
Sorry to spoil your idealized nostalgic view of the thread, but there was a duck (wireframe) on page 12 (and my own shameful contribution of semi-offtopic birds with an irrelevant lens on page 23). And, with the Zeiss' amazing microcontrast/detail, I'm sure you could find some food specks in a tight enough crop of the kid shots posted on the thread
mpmendenhall wrote:
And, with the Zeiss' amazing microcontrast/detail, I'm sure you could find some food specks in a tight enough crop of the kid shots posted on the thread
Another example of how quality optics is detrimental to the image
here we go again...
As I said, if you want to post images (not even what the thread was about from the get go) then start a fresh thread.
